Seismic node deployment system

Abstract

A seismic node deployment system comprises a cable supply with one or more seismic nodes configured for coupling to the cable at one or more attachment locations for deployment to a water column. A node attachment system is configured to drive a portion of the cable into periodic or reciprocal motion so that the attachment speed is substantially reduced relative to the speed at which the cable is deployed.

What is claimed is: 
     
       1. A seismic node deployment system comprising:
 a cable supply configured to provide a cable; for attachment of one or more seismic nodes, the one or more seismic nodes configured for coupling to the cable at an attachment location and deployment to a water column; 
 a node coupling device configured to attach the one or more seismic nodes to the cable; and 
 a coupling apparatus configured to drive the cable, wherein an attachment speed of the cable adjacent the coupling apparatus is reduced for attachment of the one or more seismic nodes relative to a deployment speed at which the cable is deployed to the water column, 
 wherein the coupling apparatus comprises a cable buffer system that alternately takes up cable length from the cable and releases the cable length to the cable, reducing the attachment speed of the cable adjacent the coupling apparatus relative to the deployment speed. 
 
     
     
       2. The seismic node deployment system of  claim 1 , wherein the cable buffer system comprises:
 a forward cable buffer that alternately takes up and releases cable length forward of the attachment of the one or more seismic nodes; and 
 an aft cable buffer that alternately takes up and releases cable length aft of the attachment of the one or more seismic nodes, 
 wherein the aft cable buffer takes up and releases cable in conjunction with and in opposition to the take up and release of cable performed by the forward cable buffer. 
 
     
     
       3. The seismic node deployment system of  claim 1 , wherein the coupling apparatus is configured to drive a portion of the cable in a reciprocating motion, such that the attachment speed of the cable adjacent the coupling apparatus is periodically increased and decreased relative to the deployment speed at which the cable is deployed to the water column. 
     
     
       4. The seismic node deployment system of  claim 3 , wherein the coupling apparatus is configured to drive the portion of the cable in the reciprocating motion longitudinally along a path of the cable defined between the cable supply and the water column, transverse to the path of the cable, or both. 
     
     
       5. The seismic node deployment system of  claim 1 , wherein one or both of: the deployment speed is substantially constant; and
 the cable supply provides the cable at a delivery speed substantially the same as the deployment speed. 
 
     
     
       6. The seismic node deployment system of  claim 1 , wherein the coupling apparatus comprises a plurality of pulley components and a reciprocating carriage, and wherein the cable is coupled to the reciprocating carriage by engagement with the plurality of pulley components. 
     
     
       7. The seismic node deployment system of  claim 6 , further comprising a mechanical drive configured to drive the plurality of pulley components such that a portion of the cable is periodically approximately stationary adjacent the coupling apparatus for attachment of the one or more seismic nodes. 
     
     
       8. The seismic node deployment system of  claim 1 , wherein the coupling apparatus comprises a plurality of pulley components and the cable makes a pass between the pulley components. 
     
     
       9. The seismic node deployment system of  claim 1 , further comprising a traction winch or cable tensioner configured to control or maintain a speed or tension at which the cable is provided by the cable supply or deployed to or recovered from the water column. 
     
     
       10. A seismic node deployment system comprising: a cable supply configured to provide a cable;
 one or more seismic nodes configured for coupling to the cable at an attachment location for deployment to a water column; 
 a node coupling device configured to attach the seismic nodes to the cable; and 
 a node attachment system configured to drive a first portion of the cable in periodic motion between the cable supply and the node coupling device and to drive a second portion of the cable in a periodic motion between the node coupling device and the water column, 
 wherein a speed of the cable is substantially reduced adjacent the attachment location relative to a speed of the cable as the cable is deployed to the water column. 
 
     
     
       11. The seismic node deployment system of  claim 10 , wherein the cable is deployed to the water column or retrieved from the water column at a substantially constant speed. 
     
     
       12. The seismic node deployment system of  claim 10 , wherein the node attachment system comprises a cable buffer system that alternately takes up cable length from the cable and releases the cable length to attach the seismic nodes. 
     
     
       13. The seismic node deployment system of  claim 12 , wherein the cable buffer system comprises:
 a forward cable buffer that alternately takes up and releases cable length forward of the attachment location; and 
 an aft cable buffer that alternately takes up and releases cable length aft of the attachment location, in conjunction with and in opposition to the take up and release performed by the forward cable buffer, such that the periodic motion is reciprocating. 
 
     
     
       14. The seismic node deployment system of  claim 12 , wherein the cable buffer system comprises a pulley around which the cable passes and a motor that drives the pulley back and forth to take up and release the cable length. 
     
     
       15. The seismic node deployment system of  claim 14 , wherein the cable buffer system further comprises a first stationary pulley around which the cable passes and a second stationary pulley spaced apart from the first stationary pulley and around which the cable passes, wherein the pulley travels transversely between the first and second stationary pulleys. 
     
     
       16. The seismic node deployment system of  claim 10 , wherein the cable supply comprises a motor-driven spool and further comprising a control system that coordinates a reciprocating motion of the first portion of the cable with a reciprocating motion of the second portion of the cable. 
     
     
       17. A seismic node deployment system comprising:
 a cable supply configured to provide a cable for attachment of one or more seismic nodes, the one or more seismic nodes configured for coupling to the cable at an attachment location and deployment to a water column; 
 a node coupling device configured to attach the one or more seismic nodes to the cable; and 
 a coupling apparatus configured to drive the cable, wherein an attachment speed of the cable adjacent the coupling apparatus is reduced for attachment of the one or more seismic nodes relative to a deployment speed at which the cable is deployed to the water column, 
 wherein the coupling apparatus comprises an aft cable buffer that alternately takes up and releases cable length aft of the attachment of the one or more seismic nodes. 
 
     
     
       18. The seismic node deployment system of  claim 17 , wherein the coupling apparatus comprises:
 a forward cable buffer that alternately takes up and releases cable length forward of the attachment of the one or more seismic nodes, 
 wherein the aft cable buffer takes up and releases cable in conjunction with and in opposition to the take up and release of cable performed by the forward cable buffer. 
 
     
     
       19. The seismic node deployment system of  claim 17 , wherein the coupling apparatus is configured to drive a portion of the cable in a reciprocating motion, such that the attachment speed of the cable adjacent the coupling apparatus is periodically increased and decreased relative to the deployment speed at which the cable is deployed to the water column. 
     
     
       20. The seismic node deployment system of  claim 19 , wherein the coupling apparatus is configured to drive the portion of the cable in the reciprocating motion longitudinally along a path of the cable defined between the cable supply and the water column, transverse to the path of the cable, or both. 
     
     
       21. The seismic node deployment system of  claim 17 , wherein one or both of: the deployment speed is substantially constant; and the cable supply provides the cable at a delivery speed substantially the same as the deployment speed. 
     
     
       22. The seismic node deployment system of  claim 17 , wherein the coupling apparatus comprises a plurality of pulley components and a reciprocating carriage, and wherein the cable is coupled to the reciprocating carriage by engagement with the plurality of pulley components. 
     
     
       23. The seismic node deployment system of  claim 22 , further comprising a mechanical drive configured to drive the plurality of pulley components such that a portion of the cable is periodically approximately stationary adjacent the coupling apparatus for attachment of the one or more seismic nodes. 
     
     
       24. The seismic node deployment system of  claim 17 , wherein the coupling apparatus comprises a plurality of pulley components and the cable makes a pass between the pulley components. 
     
     
       25. The seismic node deployment system of  claim 17 , further comprising a traction winch or cable tensioner configured to control or maintain a speed or tension at which the cable is provided by the cable supply or deployed to or recovered from the water column.